For most people, Thanksgiving is a holiday filled with traditions. The extended family arrives, the kitchen becomes a whirlwind of activity, a grand meal is staged, and everyone feasts.
Whether you stay behind to wash the dishes or recline in front of the football game following the Thanksgiving meal, the inevitable occurs: you start to feel sleepy.
No matter if it’s a long 30-minute nap or an early night to bed, Thanksgiving meal-induced sleep is just another part of the holiday. For years, many people have blamed turkey for making them sleepy.
But does eating turkey really make you sleepy?
Why Does Turkey Make You Sleepy?
If you want a quick answer, here it is: the tryptophan is not what’s causing your post-meal coma. Once you understand what tryptophan is—and the fact that it’s present in plenty of other foods—it’s clear that accusing the turkey is off-base.
What Is Tryptophan?
L-tryptophan (its official name) is a chemical in turkey that makes you sleepy. It's an amino acid that your body turns into niacin, which is a B vitamin.  Where tryptophan probably got confused with causing sleep is its association with serotonin, a neurotransmitter that’s connected to sleep, and melatonin, aka the “sleep hormone.”
However, this is a loose connection taken out of context. Here’s a great explanation from the Scientific American, who consulted neuropharmacologist Richard Wurtman of the Massachusetts Institute of Technology's Department of Brain and Cognitive Sciences:
"Turkey and other protein-rich foods contain many amino acids, and tryptophan is the scarcest among them, Wurtman says. After a Thanksgiving dinner, several amino acids circulate through the bloodstream.
To get into the brain they must be shuttled across the blood–brain barrier by specialized transport proteins. Like passengers trying to board a crowded bus, amino acids compete for rides on these transporters.
Not only does tryptophan have paltry representation among the passengers; it also competes with five other amino acids for the same transporter. Placed out by other amino acids, tryptophan thereby has a tough time hitching a ride to the brain.
Taken in isolation, tryptophan would increase brain serotonin, Wurtman says, but no food source contains tryptophan in the absence of other amino acids."
Foods with Tryptophan
Aside from losing in this “competition,” tryptophan is also found in other foods such as:
- Meats, including turkey, chicken, and fish
- Dairy products such as cheese, milk, and yogurt
- Seeds including sunflower, sesame, and pumpkin seeds
- Soybeans and more.
And since we don’t blame those foods for sleepiness throughout the year, then we can’t blame turkey either—even for that one day on the calendar.
What Makes You Sleepy on Thanksgiving?
While we can dispel the myth that tryptophan causes your sleepiness after a Thanksgiving meal, feeling the need for shut-eye is a real thing.
Here are a few potential culprits making you want to sleep:
In that same Scientific American article,  biologist H. Craig Heller (Stanford University) states that "Studies have indicated that stretching of the small intestine induces sleepiness and a protein–fat loading of the stomach induces sleepiness, and more blood going to the gastrointestinal tract means less going elsewhere.”
In other words, your parasympathetic nervous system begins to recover and conserve energy by decreasing your heart rate and blood pressure to aid digestion.
According to studies,  high-carbohydrate, high-fat meals contribute to post-meal sleepiness, with peak exhaustion occurring an hour to an hour and a half after you finish eating.
Desserts and Carbohydrates
Remember how we noted that tryptophan loses that competition? Well, desserts give it a leg up in the race to the brain. Wrapping up your meal with that piece of pecan pie means your pancreas is secreting insulin, which absorbs other amino acids in your bloodstream—except for tryptophan.
Therefore, this decrease in traffic allows more tryptophan to reach the blood-brain barrier, ultimately releasing melatonin.
All that food you consume is one thing, but it’s compounded by any wine, beer, or cocktail you’re drinking right along with it. This can potentially have you catching Zs, whether you’re kicking off the day with a glass of bubbly or finishing it off with a fine scotch.
After a few drinks, alcohol slows down the brain  and depresses your nervous system, causing you to most likely feel sleepy. 
Read More: Does Alcohol Affect Your Sleep?
Seasonal Affective Disorder
The shorter days and reduced sunlight of autumn and winter can lead to changes in mood and habits. This is because less sunlight can disrupt the body's natural circadian rhythm, which affects sleep patterns.
Seasonal affective disorder (SAD), a form of depression that typically starts in fall or winter, affects up to 3% of people.  Other symptoms of SAD include low energy, decreased enjoyment of activities, increased sleep, and increased cravings for carbohydrates.
How to Avoid the Post-Thanksgiving Food Coma
If you want to avoid falling asleep during the day or disrupting your usual night’s sleep, then timing is everything.
Earlier is always better, especially if your meal is around lunchtime. If you’re having dinner, try avoiding it too late in the evening. This makes sense when considering that your core temperature dips after lunch. Watching what you consume food- and drink-wise will help, too.
Healthy Snacks Throughout the Day
During the day, if you’re hungry, try eating small healthy snacks. This can help you not overindulge during the main meal.
Eat More Slowly
It takes about 20 minutes for your body to realize it's full. So, if you're trying to eat less, take your time and let your body register that it's had enough to eat.
Walk After Dinner
This will give you energy from the carbohydrates and make you feel better than just sitting around half asleep.
However, if you want to enjoy a Thanksgiving nap or turn into bed early, you can always just set your sleep system low and roll with it. Thanksgiving only comes once a year, so going against your chronotype for this special occasion shouldn’t be a big issue for most.
The holidays, in general, with all of the associated gatherings and parties, make it easy to get off your usual schedule. In the end, it’s up to you how much you want to allow over-consumption to affect your circadian rhythm.
To learn more about our temperature-regulating sleep systems, check out which one is best for you.
 Jenkins, T. A., Nguyen, J. C., Polglaze, K. E., & Bertrand, P. P. (2016). Influence of Tryptophan and Serotonin on Mood and Cognition with a Possible Role of the Gut-Brain Axis. Nutrients, 8(1), 56. View Study
 Ballantyne, C. (2007, October 21). Does Turkey Make You Sleepy? Retrieved from Scientific American website: View Resource
 Lehrskov, L. L., Dorph, E., Widmer, A. M., Hepprich, M., Siegenthaler, J., Timper, K., & Donath, M. Y. (2018). The role of IL-1 in postprandial fatigue. Molecular metabolism, 12, 107–112. View Study
 Alcohol. (2010). Retrieved from Medlineplus.gov website: View Resource
 Thakkar, M. M., Sharma, R., & Sahota, P. (2015). Alcohol disrupts sleep homeostasis. Alcohol (Fayetteville, N.Y.), 49(4), 299–310. View Study
  Alcohol. (2010). Retrieved from Medlineplus.gov website. View Resource